package com.lyx.liaicodemotherbackend.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.collection.CollUtil;
import cn.hutool.core.util.StrUtil;
import com.lyx.liaicodemotherbackend.exception.BusinessException;
import com.lyx.liaicodemotherbackend.exception.ErrorCode;
import com.lyx.liaicodemotherbackend.model.dto.user.UserConfirmPasswordRequest;
import com.lyx.liaicodemotherbackend.model.dto.user.UserQueryRequest;
import com.lyx.liaicodemotherbackend.model.dto.user.UserUpdateRequest;
import com.lyx.liaicodemotherbackend.model.enums.UserRoleEnum;
import com.lyx.liaicodemotherbackend.model.vo.LoginUserVO;
import com.lyx.liaicodemotherbackend.model.vo.UserVO;
import com.mybatisflex.core.query.QueryWrapper;
import com.mybatisflex.spring.service.impl.ServiceImpl;
import com.lyx.liaicodemotherbackend.model.entity.User;
import com.lyx.liaicodemotherbackend.mapper.UserMapper;
import com.lyx.liaicodemotherbackend.service.UserService;
import jakarta.servlet.http.HttpServletRequest;
import org.springframework.beans.BeanUtils;
import org.springframework.stereotype.Service;
import org.springframework.util.DigestUtils;

import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

import static com.lyx.liaicodemotherbackend.constant.UserConstant.USER_LOGIN_STATE;

/**
 * 用户 服务层实现。

 */
@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, User>  implements UserService{

    @Override
    public long userRegister(String userAccount, String userPassword, String checkPassword) {
        //1.校验
        if (StrUtil.hasBlank(userAccount, userPassword,checkPassword)) {
            throw new BusinessException(ErrorCode.PARAMS_ERROR,"参数为空");
        }
        if (userAccount.length()<4){
            throw new BusinessException(ErrorCode.PARAMS_ERROR,"用户账号过短");
        }
        if (userPassword.length()<8 || checkPassword.length()<8){
            throw new BusinessException(ErrorCode.PARAMS_ERROR,"用户密码过短");
        }
        if (!checkPassword.equals(userPassword)){
            throw new BusinessException(ErrorCode.PARAMS_ERROR,"两次输入的密码不一致");
        }
        //2.查重
        QueryWrapper queryWrapper = new QueryWrapper();
        queryWrapper.eq("userAccount", userAccount);
        // 检查账号是否存在（包括已删除的）
        User existingUser = this.mapper.selectOneByQuery(queryWrapper);
        if (existingUser != null) {
            // 无论账号是否被删除，都提示"账号已注册"
            throw new BusinessException(ErrorCode.PARAMS_ERROR, "账号已注册");
        }
        //3.加密
        String encryptPassword = getEncryptPassword(userPassword);
        //4.插数据
        User user = new User();
        user.setUserAccount(userAccount);
        user.setUserPassword(encryptPassword);
        user.setUserName("无名");
        user.setUserRole(UserRoleEnum.USER.getValue());
        boolean saveResult = this.save(user);
        if (!saveResult){
            throw new BusinessException(ErrorCode.SYSTEM_ERROR,"注册失败，数据库错误");
        }

        return user.getId();
    }

    @Override
    public LoginUserVO getLoginUserVO(User user) {
        if (user==null){
            return null;
        }
        LoginUserVO loginUserVO = new LoginUserVO();
        BeanUtils.copyProperties(user,loginUserVO);
        return loginUserVO;
    }

    @Override
    public LoginUserVO userLogin(String userAccount, String userPassword, HttpServletRequest request) {
        //1.校验
        if (StrUtil.hasBlank(userAccount, userPassword)){
            throw new BusinessException(ErrorCode.PARAMS_ERROR,"账号或密码不能为空");
        }
        if (userAccount.length()<4){
            throw new BusinessException(ErrorCode.PARAMS_ERROR,"账号错误");
        }
        if (userPassword.length()<8){
            throw new BusinessException(ErrorCode.PARAMS_ERROR,"密码错误");
        }
        //2.加密
        String encryptPassword = getEncryptPassword(userPassword);
        //查用户是否存在
        QueryWrapper queryWrapper = new QueryWrapper();
        queryWrapper.eq("userAccount", userAccount);
        queryWrapper.eq("userPassword", encryptPassword);
        User user = this.mapper.selectOneByQuery(queryWrapper);
        if (user==null){
            throw new BusinessException(ErrorCode.PARAMS_ERROR,"用户不存在或密码错误");
        }
        //3.记录登录态
        request.getSession().setAttribute(USER_LOGIN_STATE, user);
        //4.拿脱敏信息
        return this.getLoginUserVO(user);
    }

    @Override
    public User getLoginUser(HttpServletRequest request) {
        //先判断是否登录
        Object userObj = request.getSession().getAttribute(USER_LOGIN_STATE);
        User currentUser = (User) userObj;
        if (currentUser==null || currentUser.getId()==null){
            throw new BusinessException(ErrorCode.NOT_LOGIN_ERROR);
        }
        long userId = currentUser.getId();
        currentUser = this.getById(userId);
        if (currentUser==null || currentUser.getId()==null){
            throw new BusinessException(ErrorCode.NOT_LOGIN_ERROR);
        }
        return currentUser;
    }

    @Override
    public boolean userLogout(HttpServletRequest request) {
        //先判断是否登录
        Object userObj = request.getSession().getAttribute(USER_LOGIN_STATE);
        if (userObj==null){
            throw new BusinessException(ErrorCode.OPERATION_ERROR,"未登录");
        }
        request.getSession().removeAttribute(USER_LOGIN_STATE);
        return true;
    }

    public String getEncryptPassword(String userPassword) {
        //密码加盐
        final String SALT= "lyx-mlr";
        return DigestUtils.md5DigestAsHex((SALT+userPassword).getBytes(StandardCharsets.UTF_8));
    }

    @Override
    public boolean resetPassword(UserConfirmPasswordRequest userConfirmPasswordRequest) {
        //1.校验
        if (userConfirmPasswordRequest==null){
            throw new BusinessException(ErrorCode.PARAMS_ERROR,"请求参数为空");
        }
        String userAccount = userConfirmPasswordRequest.getUserAccount();
        String newPassword = userConfirmPasswordRequest.getNewPassword();
        String confirmPassword = userConfirmPasswordRequest.getConfirmPassword();
        if (StrUtil.hasBlank(newPassword,confirmPassword)){
            throw new BusinessException(ErrorCode.PARAMS_ERROR,"参数为空");
        }
        if(newPassword.length()<8){
            throw new BusinessException(ErrorCode.PARAMS_ERROR,"密码长度不能小于8位");
        }
        if(!newPassword.equals(confirmPassword)){
            throw new BusinessException(ErrorCode.PARAMS_ERROR,"两次密码不一致");
        }
        //2.据账号查用户
        QueryWrapper queryWrapper = new QueryWrapper();
        queryWrapper.eq("userAccount",userAccount);
        User user  = this.mapper.selectOneByQuery(queryWrapper);
        if (user==null){
            throw new BusinessException(ErrorCode.NOT_FOUND_ERROR,"用户不存在");
        }
        //3.加密新密码
        String encryptPassword = getEncryptPassword(newPassword);
        //4.更新密码
        user.setUserPassword(encryptPassword);
        user.setUpdateTime(java.time.LocalDateTime.now());
        boolean result = this.updateById(user);
        if (!result){
            throw new BusinessException(ErrorCode.SYSTEM_ERROR,"密码重置失败，数据库更新失败");
        }
        return true;
    }

    /**
     * 获取脱敏后单个用户信息
     *
     * @param user
     * @return com.lyx.liaicodemotherbackend.model.vo.UserVO
     * @author lyx
     * @create 2025/10/22
     **/
    @Override
    public UserVO getUserVO(User user) {
        if (user == null) {
            return null;
        }
        UserVO userVO = new UserVO();
        BeanUtil.copyProperties(user, userVO);
        return userVO;
    }
    /**
     * 获取脱敏后用户列表
     *
     * @param userList
     * @return java.util.List<com.lyx.liaicodemotherbackend.model.vo.UserVO>
     * @author lyx
     * @create 2025/10/22
     **/
    @Override
    public List<UserVO> getUserVOList(List<User> userList) {
        if (CollUtil.isEmpty(userList)) {
            return new ArrayList<>();
        }
        return userList.stream().map(this::getUserVO).collect(Collectors.toList());
    }
    /**
     * 将查询请求转换为queryWrapper对象
     *
     * @param userQueryRequest
     * @return com.mybatisflex.core.query.QueryWrapper
     * @author lyx
     * @create 2025/10/22
     **/
    @Override
    public QueryWrapper getQueryWrapper(UserQueryRequest userQueryRequest) {
        if (userQueryRequest == null) {
            throw new BusinessException(ErrorCode.PARAMS_ERROR, "请求参数为空");
        }
        Long id = userQueryRequest.getId();
        String userAccount = userQueryRequest.getUserAccount();
        String userName = userQueryRequest.getUserName();
        String userProfile = userQueryRequest.getUserProfile();
        String userRole = userQueryRequest.getUserRole();
        String sortField = userQueryRequest.getSortField();
        String sortOrder = userQueryRequest.getSortOrder();
        return QueryWrapper.create()
                .eq("id", id)
                .eq("userRole", userRole)
                .like("userAccount", userAccount)
                .like("userName", userName)
                .like("userProfile", userProfile)
                .orderBy(sortField, "ascend".equals(sortOrder));
    }

    @Override
    public boolean updateCurrentUser(UserUpdateRequest userUpdateRequest, HttpServletRequest request) {
        // 1. 参数校验
        if (userUpdateRequest == null) {
            throw new BusinessException(ErrorCode.PARAMS_ERROR, "请求参数为空");
        }
        
        // 2. 获取当前登录用户
        User currentUser = getLoginUser(request);
        
        // 3. 校验用户只能修改自己的信息
        if (userUpdateRequest.getId() != null && !userUpdateRequest.getId().equals(currentUser.getId())) {
            throw new BusinessException(ErrorCode.NO_AUTH_ERROR, "无权修改他人信息");
        }
        
        // 4. 构建更新对象
        User updateUser = new User();
        updateUser.setId(currentUser.getId());
        
        // 5. 只更新允许修改的字段
        if (userUpdateRequest.getUserName() != null) {
            updateUser.setUserName(userUpdateRequest.getUserName());
        }
        if (userUpdateRequest.getUserAvatar() != null) {
            updateUser.setUserAvatar(userUpdateRequest.getUserAvatar());
        }
        if (userUpdateRequest.getUserProfile() != null) {
            updateUser.setUserProfile(userUpdateRequest.getUserProfile());
        }
        
        // 6. 普通用户不能修改自己的角色
        // userRole 字段不进行更新
        
        // 7. 更新数据库
        boolean result = this.updateById(updateUser);
        
        // 8. 更新session中的用户信息
        if (result) {
            // 获取更新后的用户信息
            User updatedUser = this.getById(currentUser.getId());
            // 更新session
            request.getSession().setAttribute(USER_LOGIN_STATE, updatedUser);
        }
        
        return result;
    }
}
